Roth vs Traditional IRA calculator
See your after-tax retirement value side-by-side. The calculator reinvests the Traditional upfront tax deduction at the same return rate, then taxes withdrawals at your expected retirement bracket per IRS Publication 590-B distribution rules. Annual contribution defaults to the 2026 IRA limit ($7,000 under 50, $8,000 at 50 plus) set by IRS Notice 2025-67 and tabulated in IRS Publication 590-A. Roth wins whenever your retirement rate is equal to or higher than your contribution rate per 26 U.S.C. § 408A(d)(2). Last verified 2026-05-27.
| Years contributing | 35 |
| Total contributed | $245,000 |
| Gross balance at retirement | $967,658 |
| Same-dollar Traditional after withdrawal tax(Without reinvesting the deduction) | $735,420 |
The Traditional figure assumes you reinvest the upfront tax deduction at the same return and pay tax at the expected retirement rate. Without reinvesting the deduction, Traditional ends at $735K. Roth wins whenever your retirement rate is equal to or higher than your current rate, even before reinvesting the deduction.
How the math works
Roth (Pub 590-A + 590-B)
Final value equals annual contribution times the future-value annuity factor at your expected return for the years you contribute. Every dollar is yours tax-free at retirement, assuming age 59.5 and the 5-year rule per IRS Publication 590-B and 26 U.S.C. § 408A(d)(2)(A).
FVRoth = C * [((1 + r)n - 1) / r]
Traditional (Pub 590-A + 590-B)
Same formula for the gross balance, but every withdrawal is taxed as ordinary income per IRS Publication 590-B. If you reinvest the upfront 26 U.S.C. § 219 deduction at the same return, the Traditional account catches up only when your retirement rate is below your contribution rate.
FVTrad = (C * factor) * (1 - rateretire) + reinvested deduction
Limitations and what the calculator does not model
- Constant return. Real markets are volatile; 7% is a long-run S&P average, not a guarantee.
- RMDs not modelled. Traditional forces withdrawals at age 73 or 75 under SECURE 2.0 § 107 (per IRS Pub 590-B), which can push you into higher brackets. See Pub 590-B withdrawal rules.
- No state tax. Some states exempt Roth withdrawals; others tax Traditional withdrawals fully.
- No IRMAA. Medicare surcharges at MAGI over $103K (single) or $206K (MFJ) can hit Traditional retirees harder.